The invention relates to perceptual encryption of high quality compressed video sequences and more particularly to perceptual encryption of files of high quality video to generate files of restricted video as perceptually encrypted encoded data in an MPEG-1 format. The files of restricted video can either be decoded and played as restricted video or be decrypted, decoded and played as high quality video.
The MPEG standards determine the encoding and decoding conditions of motion pictures in the form of a flow of video digital data and a flow of audio digital data. The MPEG standards define the encoding conditions of motion pictures, whether associated or not with a sound signal, for storing in a memory and/or for transmitting using Hertzian waves. The MPEG standards also define the encoding conditions of the individual picture sequences that form the motion picture to be restored on a screen. Digital pictures are encoded in order to decrease the amount of corresponding data. Encoding generally uses compression techniques and motion estimation. The MPEG standards are used to store picture sequences on laser compact disks, interactive or not, or on magnetic tapes. The MPEG standards are also used to transmit pictures on telephone lines.
U.S. Pat. No. 6,205,180 teaches a device which de-multiplexes data encoded according to the MPEG standard in the form of a data flow including system packets, video packets and audio packets. The device independently organizes according to the nature (system packets, video packets and audio packets) of the data included in the packets and the storing of the data in various registers.
The encoding and decoding conditions as defined by the MPEG standards can be obtained from standard organizations. The decoding of data encoded according to one of the MPEG standards uses a separation of the data included in the data flow according to its nature. The video data is separated from the audio data, if any, and the audio and video data are separately decoded in suitable audio and video decoders. The data flow also includes system data. The system data includes information relating to the encoding conditions of the data flow and is used to configure the video and audio decoder(s) so that they correctly decode the video and audio data. The separation of the various data included in the data flow is done according to their nature. The separation is called the system layer. The system, audio and video data are separated before the individual decoding of the audio and video data.
There are current technologies for protecting the copyright of digital media are based on a full encryption of the encoded sequence. Full encryption does not allow the user any access to the data unless a key is made available.
There are alternative approaches to ensure rights protection. These approaches are based on “watermarking” techniques which aim to uniquely identify the source of a particular digital object thanks to a specific signature hidden in the bit stream and invisible to the user.
The distribution of movies for viewing in the home is one of the largest industries in the world. The rental and sale of movies on videotape is a constantly growing industry amounting to over $15 billion dollars in software sales in the United States in 1995. The most popular medium for distributing movies to the home is by videotape, such as VHF. One reason for the robust market for movies on videotape is that there is an established base of videocassette recorders in people's homes. This helps fuel an industry of local videotape rental and sale outlets around the country and worldwide. The VHS videotape format is the most popular videotape format in the world and the longevity of this standard is assured due to the sheer numbers of VHS videocassette players installed worldwide. There are other mediums for distributing movies such as laser disk and 8 mm tape. In the near future, Digital Versatile Disk (DVD) technology will probably replace some of the currently used mediums since a higher quality of video and audio would be available through digital encoding on such a disk. Another medium for distributing movies to the home is through cable television networks. These networks currently provide pay-per-view capabilities and in the near future, direct video on-demand. For the consumer, the experience of renting or buying the videotape is often frustrating due to the unavailability of the desired titles. Movie rental and sales statistics show that close to 50% of all consumers visiting a video outlet store do not find the title that they desire and either end up renting or buying an alternate title or not purchasing anything at all. This is due to the limited space for stocking many movie titles within the physical confines of the store. With limited inventory, video stores supply either the most popular titles or a small number of select titles. Increasing the inventory of movie titles is in direct proportion to the shelf capacity of any one video-store. Direct video distribution to the home is also limited by the availability of select and limited titles at predefined times. Pay-per-view services typically play a limited fare of titles at predefined times offering the consumer a very short list of options for movie viewing in the home. Video on-demand to the home is limited by the cable television head end facilities in its capacity to store a limited number of titles locally. All of the aforementioned mechanisms for distributing movies to the consumer suffer from inventory limitations. An untapped demand in movie distribution results if the inventory to the consumer can be made large enough and efficient enough to produce movies-on-demand in the format which the consumer desires. There is a need for the ability to deliver movies on-demand with a virtually unlimited library of movies on any number of mediums such as VHS videotape, 8 mm videotape, recordable laser disk or DVD. Some systems have addressed the need for distribution of digital information for local manufacturing, sale and distribution.
U.S. Pat. No. 5,909,638 teaches system which captures, stores and retrieves movies recorded in a video format and stored in a compressed digital format at a central distribution site. Remote distribution locations are connected through fiber optic connections to the central distribution site. The remote sites maybe of one of two types: a video retail store or a cable television (CATV) head end. In the case of a video retail store VHS videotapes or any other format videotapes or other video media may be manufactured on-demand in as little as three to five minutes for rental or sell-through. In a totally automated manufacturing system the customers can preview and order movies for rental and sale from video kiosks. The selected movie is either retrieved from local cache storage or downloaded from the central distribution site for manufacturing onto either a blank video-tape or a reused videotape. One feature of the system is the ability to write a two-hour videotape into a Standard Play (SP) format using a high-speed recording device. A parallel compression algorithm which is based on the MPEG-2 format is used to compress a full-length movie into a movie data file of approximately four gigabytes of storage. The movie data file can be downloaded from the central site to the remote manufacturing site and written onto a standard VHS tape using a parallel decompression engine to write the entire movie at high speeds onto a standard VHS videotape in approximately three minutes.
U.S. Pat. No. 5,793,980 teaches an audio-on-demand communication system which provides real-time playback of audio data transferred via telephone lines or other communication links. One or more audio servers include memory banks which store compressed audio data. At the request of a user at a subscriber PC, an audio server transmits the compressed audio data over the communication link to the subscriber PC. The subscriber PC receives and decompresses the transmitted audio data in less than real-time using only the processing power of the CPU within the subscriber PC. High quality audio data compressed according to loss-less compression techniques is transmitted together with normal quality audio data. Meta-data, or extra data, such as text, captions, still images, etc., is transmitted with audio data and is simultaneously displayed with corresponding audio data. The audio-on-demand system also has a table of contents which indicates significant divisions in the audio clip to be played and allows the user immediate access to audio data at the listed divisions. Servers and subscriber PCs are dynamically allocated based upon geographic location to provide the highest possible quality in the communication link.
U.S. Pat. No. 5,949,411 teaches a system which previews movies, videos and music. The system has a host data processing network connected via modem with one or more media companies and with one or more remote kiosks to transmit data between the media companies and the kiosks. A user at a remote kiosk can access the data. A touch screen and user-friendly graphics encourage use of the system. Video-images, graphics and other data received from the media companies are suitably digitized, compressed and otherwise formatted by the host for use at the kiosk. This enables movies, videos and music to be previewed at strategically located kiosks. The data can be updated or changed, as desired, from the host.
U.S. Pat. No. 6,038,316 teaches an encryption module and a decryption module for enabling the encryption and decryption of digital information. The encryption module includes logic for encrypting with a key the digital information and distributing the digital information. The decryption module includes logic for the user to receive the key. The decryption logic then uses the key to make the content available to the user.
U.S. Pat. No. 6,097,843 teaches a compression encoder which encodes an inputted image signal in accordance with the MPEG standard. The compression and decompression different is from a main compression encoding which is executed by a motion detection/compensation processing circuit, a discrete cosine transforming/quantizing circuit, and a Huffman encoding circuit. The compression and decompression are executed by a signal compressing circuit and a signal decompressing circuit. By reducing an amount of information that is written into a memory provided in association with the compression encoding apparatus, a necessary capacity of the memory can be decreased.
U.S. Pat. No. 6,064,748 teaches an apparatus for embedding and retrieving an additional data bit-stream in an embedded data stream, such as MPEG. The embedded data is processed and a selected parameter in the header portion of the encoded data stream is varied according to the embedded information bit pattern. Optimization of the encoded data stream is not significantly affected. The embedded information is robust in that the encoded data stream would need to be decoded and re-encoded in order to change a bit of the embedded information. As relevant portions of the header are not scrambled to facilitate searching and navigation through the encoded data stream, the embedded data can generally be retrieved even when the encoded data stream is scrambled.
U.S. Pat. No. 6,115,689 teaches an encoder and a decoder. The encoder includes a multi-resolution transform processor, such as a modulated lapped transform (MLT) transform processor, a weighting processor, a uniform quantizer, a masking threshold spectrum processor, an entropy encoder and a communication device, such as a multiplexor (MUX) for multiplexing (combining) signals received from the above components for transmission over a single medium. The decoder includes inverse components of the encoder, such as an inverse multi-resolution transform processor, an inverse weighting processor, an inverse uniform quantizer, an inverse masking threshold spectrum processor, an inverse entropy encoder, and an inverse MUX.
U.S. Pat. No. 5,742,599 teaches a method which supports constant bit rate encoded MPEG-2 transport over local Asynchronous Transfer Mode (ATM) networks. The method encapsulates constant bit rate encoded MPEG-2 transport packets, which are 188 bytes is size, in an ATM AAL-5 Protocol Data Unit (PDU), which is 65,535 bytes in size. The method and system includes inserting a plurality of MPEG-2 transport packets into a single AAL-5 PDU, inserting a segment trailer into the ATM packet after every two MPEG packets, and then inserting an ATM trailer at the end of the ATM packet. MPEG-2 transport packets are packed into one AAL-5 PDU to yield a throughput 70.36 and 78.98 Mbits/sec, respectively, thereby supporting fast forward and backward playing of MPEG-2 movies via ATM networks.
U.S. Pat. No. 6,157,625 teaches in an MPEG transport stream, each audio signal packet is placed after the corresponding video signal packet when audio and video transport streams are multiplexed.
U.S. Pat. No. 6,157,674 teaches an encoder which compresses and encodes audio and/or video data by the MPEG-2 system, multiplexing the same and transmitting the resultant data via a digital line. When generating a transport stream for transmitting a PES packet of the MPEG-2 system, the amounts of the compressed video data and the compressed audio data are defined as whole multiples of the amount of the transport packet (188 bytes) of the MPEG-2 system, thereby to bring the boundary of the frame cycle of the audio and/or video data and the boundary of the transport packet into coincidence.
U.S. Pat. No. 6,092,107 teaches a system which allows for playing/browsing coded audiovisual objects, such as the parametric system of MPEG-4.
The inventors incorporate the teachings of the above-cited patents into this specification.